Displaying JSON data in HTML

I am trying to write this small bit of javascript so that it will drag in information off this json/xml file and display it to the user in normal text language. (was previously someone elses work, so lost in slight confusion)

I just want to know how to direct the data onto the page... The Url to the data in a json&/xml format is known and can be worked out using a certain format with the url link.